Self-cloning crayfish

Ten-legged all female crayfish are descended from one single female with a mutation allowing it to reproduce without males said a new study.

These self-cloning ladies are found for sale in North America, despite a warning against keeping them as pets, BBC reports.

Study found that marbled crayfish are multiplying rapidly and invading ecosystems across the world.

Sales of the six-inch creature are already banned by the European Union.

Procambarus virginalis did not exist three decades ago.

Now officially a separate species, the marbled crayfish can been
found in the wild in Japan, Madagascar, multiple European countries and
the US.

The new study published in Nature, Ecology and
Evolution describes the invasive species as a threat to wild ones,
particularly seven native species in Madagascar.

Born to a male and female slough crayfish, a species originally from Florida, the original marbled crayfish had an additional set of chromosomes - a mutation that made her distinct from her parents and allowed her to reproduce without having to mate.

"If you have one animal, essentially, three months later, you will have 200 or 300," Dr Wolfgang Stein, one of the researchers, told Canadian public poadcaster CBC.

Dr Stein, who is a neurophysiologist at Illinois State University, told the BBC that they compared 11 marbled crayfish, spread through the pet trade to four locations on three continents.

He noted that while they all share the DNA of one mother crayfish, there were some differences in "colouring".

"The animal sequenced here by us in the US was more blue-ish than the ones from Germany and Madagascar," Dr Stein said.

He believes this is where environmental influences may play a role in shaping the unique past of this freshwater crayfish's life. "[Raised] in solitude they have a tendency to be blue", and those socialised with others in their species tended to be more grey, he explained.

Curiously, scientists at the German Cancer Research Centre, that led the study, may be able to better understand how cancer tumours adapt and develop resistance to drug treatments, by studying the crayfish's adaptability and ability to multiply.

The crustaceans can be bought in pet shops in North America and through online adverts. One online seller from Ontario offered a one-inch self-cloning marbled crayfish for free and five larger ones for C$20 ($16; £11.50).

While there is not yet a wild population of marbled crayfish in Canada, the department of fisheries and oceans warned that it would be illegal to release any unwanted crayfish into the wild.

"Based on what is known about the reproductive behaviour of the marbled crayfish, we do not recommend Canadians keep these animals as pets," Becky Cudmore, of the fisheries and oceans department, told CBC.